pharm Exam 3, chpt 14,15

Overview of Medications

• Different classes of medications used for anxiety and related conditions include:

  • Benzodiazepines

  • Antidepressants

  • SSRIs

  • SNRIs

  • Non-benzodiazepines

  • Barbiturates

Benzodiazepines

• Definition: Antianxiety drugs primarily prescribed for acute anxiety, sedation, muscle relaxation, seizures, and alcohol withdrawal.

• Mechanism of Action:

  • Binds to cell receptors enhancing the effects of GABA (Gamma-Aminobutyric Acid), an inhibitory neurotransmitter that slows and calms brain activity.

• Examples of Benzodiazepines:

  • Lorazepam

  • Generic name: Lorazepam

  • Trade name: Ativan

  • Notable ending: "zepam"

  • Alprazolam

  • Generic name: Alprazolam

  • Trade name: Xanax

  • Notable ending: "zolam"

• Overdose treatment:

  • Antidote for benzodiazepine overdose: Flumazenil (spelled f-l-u-m-a-z-e-n-i-l).

• Adverse Drug Reactions:

  • Mild drowsiness

  • Sedation

  • Lightheadedness

  • Ataxia

  • Visual disturbances

  • Restlessness

  • Nausea

  • Constipation

  • Diarrhea

  • Lethargy

  • Fatigue

  • Dry mouth

• Administration Considerations for Lorazepam:

  • When administered IV, monitor respirations every 5-15 minutes.

  • Have airway and resuscitation equipment accessible.

• Contraindications:

  • Pregnancy

  • Lactation

  • Elderly (increased dementia risk)

  • Impaired liver or kidney function

• Nursing Considerations:

  • Take at night if dizziness/drowsiness occurs.

  • Rise slowly from a sitting/lying position.

  • Avoid driving or operating heavy machinery.

• Drug Interactions:

  • Concurrent use with CNS depressants can enhance sedative effects and increase the risk of respiratory depression and death.

• Long-term Use Risks:

  • Not intended for long-term therapy due to increasing dependency and tolerance.

  • Taper dosage down for discontinuation.

  • Withdrawal symptoms include increased heart rate, anxiety, hypertension, fever, sweating, decreased memory, agitation, seizures, tremors, insomnia, vomiting.

Antidepressants

• SSRIs (Selective Serotonin Reuptake Inhibitors):

  • Example:

  • Escitalopram

    • Generic name: Escitalopram

    • Trade name: Lexapro

  • Mechanism of Action: Inhibits the uptake of serotonin, thus increasing its availability.

  • Indications: Treatment for depression and anxiety.

  • Onset: 4-6 weeks for effect.

  • Adverse Effects: Dizziness, nausea, insomnia, confusion, and seizures.

  • Contraindications: Contraindicated in breastfeeding and if used within 14 days of MAOI therapy.

  • Drug Interactions:

  • Risk of serotonin syndrome and hypertensive crisis when used with MAOIs.

  • Not recommended with St. John's wort.

  • Signs of Serotonin Syndrome: Tachycardia, increased blood pressure, mental status changes, muscle rigidity, sweating.

Non-Benzodiazepines

• Example:

  • Zolpidem

  • Generic name: Zolpidem

  • Trade name: Ambien

  • Classification: Sedative hypnotic

  • Primary Indication: Short-term management of insomnia.

  • Administration: Take immediately before bedtime.

  • Common Adverse Effects: Dizziness, headache, drowsiness, behavioral changes, and nocturnal eating.

  • Overdose Treatment: Supportive measures, possible gastric lavage.

Tricyclic Antidepressants (TCAs)

• Example:

  • Imipramine

  • Generic name: Imipramine

  • Trade name: Tofranil

  • Mechanism of Action: Blocks the reuptake of serotonin and norepinephrine.

  • Adverse Effects: Include anticholinergic effects such as constipation, dry mouth, drowsiness, blurred vision, and orthostatic hypotension.

  • Contraindications:

  • Cardiac conditions

  • Elderly patients

  • Drug Interactions: Concurrent use with CNS depressants may cause sedation.

Monoamine Oxidase Inhibitors (MAOIs)

• Example:

  • Phenelzine

  • Generic name: Phenelzine

  • Trade name: Nardil

  • Mechanism of Action: Blocks monoamine oxidase, increasing levels of epinephrine, norepinephrine, dopamine, and serotonin.

  • Common Side Effects: Orthostatic hypotension, headache, dizziness, and dry mouth.

  • Precautions: Avoid tyramine-rich foods to prevent hypertensive crisis.

Mood Stabilizers for Bipolar Disorder

• Example:

  • Lithium

  • Therapeutic range: 0.6 to 1.2 mEq/L.

  • Adverse Reactions: Nausea, drowsiness, fatigue, increased thirst, and weight gain.

  • Toxicity Levels:

  • Mild: 1.5 to 2 mEq/L

  • Moderate: 2 to 3 mEq/L

  • Severe: > 3 mEq/L

  • Signs of Toxicity: Confusion, blurred vision, tinnitus, slurred speech, excessive urination, tremors, ataxia.

  • Contraindications: Pregnancy, renal and cardiovascular disease, excessive diarrhea or vomiting.

  • Nursing Education: Patients should carry ID indicating lithium use and have regular lithium level checks every 1-2 months.

Attention Deficit Hyperactivity Disorder (ADHD) Medications

• Example:

  • Methylphenidate

  • Trade names: Concerta, Ritalin.

  • Mechanism of Action: Improves focus and attention by releasing neurotransmitters like norepinephrine and dopamine.

  • Onset: Less than 60 minutes.

  • Adverse Effects: Irregular heartbeat, increased heart rate, potential for dependence.

  • Periodic Drug Holidays: Recommended to minimize the risk of dependence, applicable to both children and adults.

  • Contraindications: Severe anxiety, agitation, psychosis, suicidal ideation, glaucoma, Tourette syndrome.

  • Drug Interactions: Decreases effectiveness of anticonvulsants and anticoagulants, and can lead to hypertensive crises when combined with MAOIs.